ABSTRACT Ovarian cancer is the deadliest of all gynecologic malignancies, estimated to be the cause of death in more than 125,000 women annually. Long-term survival rates have not improved as ovarian cancer continues to lack satisfying biomarkers for targeted therapies, demonstrating the significance of better diagnostic and therapeutic tools to treat this gynecological disease. Loss of the p150 protein (product of SALL2 gene) is observed in many cases of human ovarian carcinoma, whereas normal ovarian epithelial cells maintain high levels of p150, supporting an important tumor suppressive role for p150 in the human ovary. The p150 and p53 proteins share growth arrest and pro-apoptotic functions by independently inducing p21Cip1/Waf1 and BAX, and both proteins are targeted by human papilloma virus type 16, resulting in blockage of growth arrest in infected cells. Therefore, p150 seems to have strong potential as a novel cancer biomarker for early diagnosis and risk prediction, but its roles in the regulatory mechanisms of cancer cell growth have not been fully examined to date. In this study, I propose to focus our investigation on a novel function of p150 in DNA replication, a function not shared by p53 or other known tumor suppressors (Specific Aim I). We also seek to develop a new epigenetic technology that selectively targets the SALL2 promoter in human ovarian carcinomas (Specific Aim II). Results from the completion of the proposed studies will enable the discovery of new roles of p150 in inhibition of DNA replication in human ovarian cells. The proposed research projects will also enable a rich and widely-applicable understanding of epigenetic technologies for the suppression of cancer cell growth.